Telephone system



Dec. 21, 1927. r 1,653,931

' A. SCHLURMANN TELEPHONE sYs'rEu' Filed Jun- 16 1.924

--Im.ren Ur 11371152 Schlurma nn Patented Dec. 27, 1927.

UNITED STATES PATENT OFFICE.

r p AUGUST SCHLURMANN, 0F BERLIN-CHARLOTTENBURG, GERMANY, ASSIGNOR T0 SIEMENS. & HALSKE AKTIENGESELLSCHAFT WERNERWERK, OF SIEMENSSTADT,

BEI BERLIN, GERMANY.

TELEPHONE SYSTEM.

Application filed June 16, 1924, Serial No.

. The invention relates to a circuit arrange ment for telephone systems having several automatic exchanges accessible over an operators position, these automatic exchanges being arranged for operation with different types of current impulses.

The present invention differs from known circuits for such systems in that the connecting devices at the operators position are provided with switching devices, which operate after a trunk line leading to an automatic exchange has been taken into use and effect circuit changes at the impulse sender, so that current impulses can be transmitted of a type appropriate to the automatic exchange that has been connected up.

One method of carrying out the invention is shown in the drawing, from which all details have been omitted that'do not form part of the invention.

The operators position at a telephone exchange is designated by PL and a cord circuit belonging to this position is designated by Sch. The jack Kl 1 leads to an automatic exchange having switches arranged for operation by earth impulses, while the jack Kl 2 leads to an automatic exchange WA 1 having switches arranged for operation on the loop system. When the operator throws her connecting key VS and operates her number dial for positioning the switches (not shown) at the wanted exchange, the relays F and H or the relay L are operated dependent upon whether the operator at the position PL inserts her connecting plug Vet into the jack Kl 1 or the jack KZ 2. The switching relays F and H or the relay L 'are operated whereby circuitv changes are brought about at the impulse sender, whichenable impulses to be transmitted which are suitable for the exchange that has been connected up. The line is tested for its engaged condition over the c-lead in known manner. If the lineis free, the test relay P and the relay G or C1 operate. By short c'ircuiting one of its windings, the relay P marks the line taken into use engaged to other switches that are set on to the line. C completes the not shown test circuit of the switch GW (group selectpr), whereupon the latter connects with the trunk going to the switch LW (final selector) correspond- 720,180, and in Germany August 21, 1923.

ing to the positioning impulses transmitted; thereupon LW is set on to the selected line by the transmission of further impulses in a manner known and therefore not shown. The relays F and H for efiecting the circult changes at the impulse sender are automatically released after LW. has been positioned, this being done by means of the relay R, which is then energized.

The method of operating isas follows:

By way of example let it be assumed that the operator at the position PL has been requested to set up a connection with a subscriber (not shown), who can be reached over trunk lines, e. g. VL, leadin to an automatic exchange and connecte to jacks, such for instance as the jack KZ 1. For setting up the connection, the operator inserts the connecting plug VSt of the cord circuit Sch into the jack K1 1, and by throwing the connecting key closes the contacts as 1, 12s 2. The following circuit is thereby comleted: earth, winding I of the relay F, ack contact 7L3, back contact Z 4, contact cs 2 of the connecting key, plug VSt, jack Kl 1, a-1ead of; the trunk line VL, contact p5, winding of the relay A, battery, earth. The relay A prepares an operating circuit for the automatic switches at WA. The relay F operates and closes its ,front contact f6, whereby when the operator now operates her number dial (not shown), and closes the contact n7, circuit is established for the slow acting relay H: earth, battery, winding of relay H, contact 027, front contact f6, contact as 1,'plug VSt, jack KZ 1, b-lead of the trunk line VL, contact 28, winding of relay B, earth. The relay operates over this circuit toprepare for the establishment of "the usual setting circuits in the usual manner. The relay H operates and at its contact k9 closes the following holding circuit for itself and for the relay F and the winding I of F is. disconnected by the opening of the contact k3: earth, contact 719, back contact r10, windings II of the relays H and F, battery, earth. The relays P andC operate over the '0 lead if the line is free: earth, windings II and I of P, plug VSt, jack Kl 1, a lead, winding of C, battery, earth. By closing its contact 1011, relay P marks the line taken into use cnaged to other switches that are set on the ine. C completes the test circuit for the switch 'GW in known manner, which is not shown.- The relay R cannot be energized, because the contact 1112 of the number dial is open. After the winding I of F has been disconnected at the contact b3, the current impulses are sent from earth over the impulse contact 7118. With each interruption of current at. the contacts 118 the relay A falls back and in the usual manner causes the operation ofthe automatic switch GW. The switch GW having been set on a line a, I) going to a switch LW by means of impulses transmitted by the operator, the switch LW is positionedby the transmission of further impulses in known manner, which likewise is not shown. When the ositionin of LW has been completed and t e selecte line has been ascertained to be free, the relay It operates in the following circuit with the not shown side switch in the position on: earth, battery, winding of B, back contact n12, which is now closed after the transmission of current impulses, front contact.

h13, contact as 2, plug VSt, jack Kl 1, a lead, contact p14, wiper of GW, lead a, side switch position a:, resistance W, earth. R opens its contact r10 and thereby breaks the circuit of the switching relays H and F. The operator then restores the dialing key VSl and VS2 thereby reconnecting the talking conductors of the cord PL and enabling conversation to take place over the connection. At the end of the conversation, the o erator receives the clearing signal in any own manner, whereu on on withdrawin the connecting plug St from the jack K 1, she effects the release of the other switches used for the call.

If, however, the wanted subscriber is to be reached over trunk lines, for examkple VLl connected to jacks such as jack l 2 for exam le, the operator inserts the connecting p ug VSt of her cord circuit Sch into the jack Kl 2. In that case the following circuit is established after she has thrown her connecting key: earth, winding of the switching relay L, impulse contact 415, back contact fl6, contact as 1 of the connecting key, plug VSt, jack Kl 2, lead 61 of the trunk line VLl, winding of the relay A1, battery, earth. The relay F in this case is short circuited\by the earthed resistance W1 connected to the lead al. The relay L however operates in the circuit described and closes a holding circuit for itself from earth, battery over its winding II, front contact Z17, contact as 2, plug VSt, 'ack Kl 2,lead a1, re sistance W1, earth.

he impulses for positioning the switches are now transmitted in the manner suitable for the exchange connected up. The testing of the line taken into se takes place over the lead 01, whereupon in the manner before described, the test relay P and the circuit, an impulsing circuit for one of said trunk lines extending over one of said talking conductors, a second impulsing circuit for the second of said trunk lines extending over the, other of said talking conductors, and means for transmitting impulses over either one of said impulsing circuits to said trunk lines dependent upon which of said trunk lines sald cord circuit is connected with.

2. In a telephone system, a cord circuit having a pair of talking conductors, a calling device associated with said cord circuit, two trunk lines of different character terminating in jacks and accessible to said cord circuit, an'impulsing circuit for one of said trunk lines extending over one of said talking conductors, a second impulsing circuit for the second of said trunk lines extending over the other of said talking conductors,

a relay in said cord circuit operated re-' sponsive to the connectionof said cord circuit with one of said trunk lines for select- ,ing the first of said impulsing circuits and ,one of said impulse circuits extending over one talking conductor of said cord circuit and the other of said impulse circuits extending over the other talkin conductor of said cord circuit, two trunk lines, means responsive to the connection of said cord circuit with one of said trunk lines for selecting one of said impulse circuits and dis abling the other, and means responsive to the connection of said cord circuit with said other trunk line for selecting said other impulse circuit and disabling said first impulse circuit.

4:. In a telephone system, a cord circuit, two impulse circuits in said cord circuit, one of said impulse circuits extending over one talking conductor of said cord circuit and the other of said impulse circuits extending over, the other talking conductor of said cord circuit, two trunk lines, means responsive to the connection of said cordcircuit with one of said trunk lines for selecting one of said impulse circuits and disabling the other, means responsive to the connection of said cord circuit with said other trunk line for selecting said other impulse circuit and disabling said first impulse circuit, and a calling device associated with said cord circuit for transmitting impulses over either of said impulse circuits to the respectivetrunk lines.

5. In a telephone system two trunk lines, two jacks one for each trunk line, an operator s cord circuit, two impulsing circuits in said cord circuit, means responsive to the insertion of the plug of said cord circuit into one of said jacks for selecting one of said impulsing circuits, and means responsive to the insertion of said other of said jacks for selecting theother of said impulsmg circuits.

6. In a telephone system, two trunk lines of diflerent character, an operators cord circuit and calling device, and means responsive to the connection of said cord circuit with either one of said trunk lines for adapting the impulsing circuit of said calling device to conform with the character'of said trunk line connected with.

7. In a telephone system, a first trunk line, a second trunk line, a cord circuit, a calling device in said cord circuit, means for connecting said cord circuitwith either one of said trunk lines, and means in said cord circuit operated responsive to such connection for changing the impulse circuit of said calling device from one talking conductor of the cord circuit to the other dependent upon which trunk line is connected with.

8. In a telephone system, a cord circuit having a pair of talking conductors, a call- 1 ing device associated with said cord circuit,

two trunk lines, means for connecting said cord circuit with either of said trunk lines, and circuit arrangements depend.- ent upon which trunk line the said cord circuit is connected with for transmitting impulses over one or the other of the talking conductors of said cord circuit to the connected trunk line when said calling device is operated.

9. In a telephone system, a first exchange, a second exchange and a third exchange, trunk lines connecting the first and second and the first and third exchanges, automatic switches in the second and third exchanges for extending said trunk lines into connec tion with subscribers lines, an operators cord circuit at the first exchange, two independent impulse control circuits each including a diflerent talkin conductor of said cord circuit, and means w ereby the operator plug into the switches of di can control over one of said circuits only the switches in said second exchange and over the other of said circuits only the switches in said third exchange.

10. Ina telephone system, a trunk line terminatin in a two wire switch, a second trunk line terminating in a three wire switch, a calling device and means for connecting it to either trunk line, and means for automatically controlling the circuits of the calling device in accordance with the trunk connected with so that it is adapted to send two wire impulses to the two wire .switch and three wire impulses to the ",three wire switch.

, 11. In a telephone system, switches responsive to impulses in an open control circuit, other switches responsive to interruptions in a closed control circuit, and a single calling device for controlling both types of switches and having means for producing efit'ective impulses or interruptions depending on the type of switch'being controlled. 12. In a tele hone system, two automatic fl erent types, a calling device having two sets of impulse sprin s, one set for use with one type of switch an the other set for use with the other. ty e of switch, means for connecting said ca ing device to either one of said switches,-and means dependent upon which switch said calling device is connected with for automatically selecting the proper set of impulse springs. 13. In a telephone system, two automatic switches of different types, a calling device having two sets of impulse springs, one set for use with one type of switch and the other set for use with the other ty e of switch,

means for connecting said calhng device to either one of said switches, and means dependent upon which switch said calling device is connected with for automatically selecting the proper setof impulse springs, one of said sets of impulse sprlngs being a normally open pair of impulse springs and the other set being a'normally closed pair of impulse springs;

14. In a telephone system, an automatic switch adapted to be operated by current impulses, a second automatic switch adapted to be operated by the current interruptions, and a single callingdevice for producing either impulses or interruptions dependent upon which switch said calling device is connected with.

15. In a telephone system, two trunks, a dialing circuit adapted to function in a different manner with each of said trunks, a cord circuit, and means associated with said cord circuit for discriminating between said trunks to condition said dialing circuit to function therewith.

16. In a telephone system, a cord circuit adapted to function with a plurality of trunk circuits, said trunk circuits having difierent dialing characteristics, dialing equi ment, and discriminating means associate with said cord circuit and responsive to the association of said cord with any of said trunk circuits for conditioning said dialing equipment to function with the trunk circuit cmployed.

17. In a telephone system, a plurality of trunk circuits having difl'erent dialing char- 10 acteristics, a cord circuit, a dial circuit for dialing over either of said trunks, a key for connecting the dial circuit to the cord, and means operative responsive to the connection of said cord circuit with one of said trunk circuits and the actuation of said key for conditioning said dial circuit to supply dialing impulses of the required charactcn istics for the trunk circuit taken for use.

In testimony whereof I aflix m si ature.

AUG. SCHLUfi NN. 

